Senior Java Backend Engineer

About the Company 

We’re Source Angel - a Danish-rooted software company with development centers in Ukraine, Poland, and Romania. For 8+ years, we’ve been building dedicated tech teams for global clients, focusing on long-term partnerships and a strong people-first culture. 

We foster an environment of respect, transparency, and professional growth, offering engineers freedom with responsibility, collaborative Scandinavian leadership, and an international mindset. 

About the Project 

Be one of the first on a fresh team for a Nordic client — entrepreneurial energy, proven foundation. 

You’ll join a newly formed core team that is rebuilding a widely-used automotive SaaS platform from scratch using modern technologies and AI-first development principles. 

The system supports over 1,500 car repair shops across Europe — from workshop management to integrations with finance, logistics, and more. The client is part of a global software group (190+ companies in 34 countries), which offers long-term stability, strategic support, and room for innovation, while keeping full autonomy in the local product strategy. 

This is a long-term greenfield modernization project with high technical standards and a strong emphasis on scalability, security, clean architecture, and future AI integration. 

The tech stack is still evolving, and you'll have the opportunity to actively shape it. 

What You’ll Do 

• Design and build microservices using DDD (Domain-Driven Design) 
• Define and maintain REST/GraphQL APIs with OpenAPI or similar 
• Collaborate with DevOps to implement CI/CD, containerization, and GitOps workflows 
• Set up observability and metrics using Prometheus, Grafana, Loki, Jaeger 
• Integrate security/auth using OAuth2, OIDC, SCIM 
• Participate in architecture reviews, mentoring, and documentation 
• Help migrate legacy systems to a new cloud-native platform 
• Work closely with a Danish-based tech lead and distributed team 

Tech Stack 

• Languages: Java 21 + Spring Boot 3 (main), also Go / Node.js in parts 
• Infrastructure: Docker, Kubernetes (Helm/Terraform), OVH or managed cloud 
• Databases: PostgreSQL, MongoDB, Cassandra 
• Messaging: RabbitMQ (initial), Kafka (future) 
• CI/CD: GitHub Actions, ArgoCD, GitLab CI 
• Security: Zitadel (OAuth2/OIDC) 
• Observability: Prometheus, Loki, OpenTelemetry, Jaeger, Grafana 
• Docs/Planning: Jira, Confluence, Markdown/AsciiDoc 

What We’re Looking For 

• 5+ years of backend development experience 
• Proficiency in Java and microservices architecture 
• Solid experience with Kubernetes, Terraform, Docker 
• Strong awareness of security best practices in backend and cloud-native environments 
• Understanding of scalable systems and API design 
• Experience working in agile, distributed teams 
• Fluent English communication across distributed teams  

Bonus if you have: 

• Experience with AI/ML integration or event-driven systems 
• Background in multi-tenant SaaS platforms 

Onboarding & Performance Expectations 

First 30 Days 

• Collaborate with the team to define architecture standards, CI/CD pipelines, and observability tooling 
• Develop a functional microservice prototype following agreed design patterns and platform technologies 

First 90 Days 

(to be refined together with the candidate based on strengths and focus areas) 

• Take ownership of migrating one or more critical legacy services to the new architecture 
• Share insights, technical recommendations, and improvement ideas based on hands-on experience 

Ongoing Success Metrics 

• Will be defined collaboratively with the candidate and reviewed regularly to ensure mutual alignment and growth 

Why Join Us 

• Work on a greenfield rebuild of a successful international platform 
• Take ownership from day one in a flat, transparent environment 
• Long-term opportunity with a stable, well-funded product 
• Collaborate with an experienced and supportive multinational team 
• Opportunity for future relocation to Denmark or other projects around the world 

We Offer: 

• Exciting projects with Denmark’s most dynamic clients 
• We provide the necessary equipment for your work 
• For B2B contractors, we also assist with opening and maintaining your sole proprietorship (jednoosobowa działalność gospodarcza) in Poland 
• An attractive salary package matching your experience and responsibilities 
• Office located centrally in Warsaw 
• Flexible work location can be arranged in coordination with the team lead 
• 20 days of paid vacation 
• Paid sick leave  
• Medical insurance 
• Local Danish managers offering mentorship and helping you grow communication and interpersonal skills